Harry Brook in line to replace Ollie Pope as England vice-captain for the Ashes

Pope has been Ben Stokes' understudy since 2023, and has skippered England on five occasions in Test matches.

Brook is England's current white-ball captain and is thought to have impressed McCullum enough to be given more of a leadership role in the longest format.

Speaking to reporters, England's mentor said: "We will chat about that over the coming days, as we finalise our Ashes squad. You're always looking at things, right? Every time you get together with a series, you discuss things.

"I think it's no secret that Harry Brook is emerging as a leader within English cricket, so that's something we need to work out. But whatever happens, a great team man understands that just because you haven't got a title, doesn't stop you from being a leader.

"I've enjoyed working with Brooky, I think he's taken to the role really well, really quickly. Still a work in progress but he's got a demanding schedule himself and we have to be aware of that as we move forward.

"He's got a good head on his shoulders, he's well connected within the group. He keeps things very simple. We've got a really good relationship and I think that started well."

McCullum will miss the upcoming T20I series in Ireland to take a break, with assistant coaches Jeetan Patel and Marcus Trescothick taking charge of the national side.

The former New Zealand wicketkeeper-batter will refresh ahead of his maiden Ashes tour, which he says will a "ripper".

McCullum added: "I thought it would be exciting. We're very keen to make sure that we treat every series in isolation and give it the respect and the focus it deserves, because the minute you get too far in front of yourself, you're going to get your arse kicked.

"So we always deliberately try and do that. But now the Ashes is our next assignment in the Test team, so we can't wait. It's going to be awesome.

"We try to do our best to insulate the environment, on good days and bad, from a lot of that noise and we know the noise is going to be extreme. But it doesn't mean we're not excited about that.

"It's going to be a huge series and we go down there with the type of team that we want. We'll give ourselves every chance against the very, very good Australian side in their own conditions. It's going to be a ripper."